Coordination of several distributed system components is an error-prone task, since interaction of several simple components can generate rather sophisticated behavior. Verification of such systems is very difficult or even impossible because of the so-called state space explosion problem, when the size of the system reachability set grows exponentially on the number of interacting agents. To overcome this problem several approaches to construct correct models of interacting agents in a compositional way were proposed in the literature. They define different properties and conditions to ensure correct behavior of interacting agents. Checking these conditions may be in its turn quite a problem.In this paper we propose patterns for correct composition of component models. For justifying these patterns we use special net morphisms. However, to apply patterns the user does not need to be familiar with the underlying theory.

In this paper, we present an approach to model and simulate models of multi-agent systems (MAS) using Petri nets. A MAS is modeled as a set of workflow nets. The agent-toagent interactions are described by means of an interface. It is a logical formula over atomic interaction constraints specifying the order of inner agent actions. Our study considers positive and negative interaction rules. In this work, we study interfaces describing acyclic agent interactions. We propose an algorithm for simulating the MAS with respect to a given interface. The algorithm is implemented as a ProM 6 plug-in that allows one to generate a set of event logs. We suggest our approach to be used for evaluating process discovery techniques against the quality of obtained models since this research area is on the rise. The proposed approach can be used for process discovery algorithms concerning internal agent interactions of the MAS.

Abstract. Process mining offers various tools for studying process-aware information systems. They mainly involve several participants (or agents) managing and executing operations on the basis of process models. To reveal the actual behavior of agents, we can use process discovery. However, for large-scale processes, it does not yield models, which help understand how agents interact since they are independent and their concurrent implementation can lead to a very sophisticated behavior. To overcome this problem, we propose interface patterns, which allow getting models of multi-agent processes with a clearly identified agent behavior and interaction scheme as well. The correctness of patterns is provided via morphisms. We also conduct a preliminary experiment, results of which are highly competitive compared to the process discovery without interface patterns.

Structural transformations that preserve properties of formal models of concurrent systems make their verification easier. We define structural transformations that allow to abstract and refine elementary net systems. Relations between abstract models and their refinements are formalized using morphisms. Transformations proposed in this paper induce morphisms between elementary net systems as well as preserve their behavioral properties. We also show application of the proposed transformations to the construction of a correct composition of interacting workflow net components.